Khodakaram-Tafti A, López A
Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Ave. Charlottetown, PEI, Canada C1A 4P3.
J Vet Med A Physiol Pathol Clin Med. 2004 Feb;51(1):10-4. doi: 10.1111/j.1439-0442.2004.00596.x.
Histology and immunohistochemistry were used to analyse the lesions and distribution of Mycoplasma bovis antigen in the lungs of 18 naturally infected calves. Microscopic examination of pneumonic lungs revealed two distinct patterns of necrosis and inflammation. The first pattern was observed in six of 18 (33.3%) calves in which microscopic lesions were characterized by large irregular areas of coagulative necrosis surrounded by a dense zone of degenerated neutrophils. Moderate amounts of mycoplasmal antigen were in the centre and periphery of these necrotic foci and, to a lesser extent, in mononuclear cells of the peribronchial lymphoid tissue. The second pattern was observed in 18 of 18 (100%) calves and consisted of rounded foci of caseous necrosis composed by granular eosinophilic material surrounded by a rim of granulation tissue. Large amounts of M. bovis antigen were detected in the centre and periphery of these necrotic foci and, to a lesser extent, in the peribronchial lymphoid tissue, and alveolar and interstitial macrophages. It was concluded that both caseous and coagulative necrosis of the lung parenchyma was primarily caused by M. bovis. Infection with M. bovis should be suspected in bovine necrotic bronchopneumonia, particularly in cases in which the pulmonary necrosis is part of a pyogranulomatous inflammation centred around airways. The pattern of caseous necrosis with pyogranulomatous inflammation is characteristic of M. bovis infection while the pattern of coagulative necrosis is similar to and must be differentiated from Mannheimia haemolytica and Haemophilus somnus infection.
采用组织学和免疫组织化学方法分析了18头自然感染牛支原体的犊牛肺脏中病变及牛支原体抗原的分布情况。对肺炎肺脏进行显微镜检查发现了两种不同的坏死和炎症模式。第一种模式在18头犊牛中的6头（33.3%）中观察到，其中显微镜下病变的特征是大片不规则的凝固性坏死区域，周围是密集的变性中性粒细胞区。在这些坏死灶的中央和周边有中等量的支原体抗原，在较小程度上也存在于支气管周围淋巴组织的单核细胞中。第二种模式在18头犊牛中的18头（100%）中观察到，由干酪样坏死的圆形病灶组成，病灶由颗粒状嗜酸性物质构成，周围有一层肉芽组织。在这些坏死灶的中央和周边检测到大量牛支原体抗原，在较小程度上也存在于支气管周围淋巴组织、肺泡和间质巨噬细胞中。得出的结论是，肺实质的干酪样坏死和凝固性坏死主要由牛支原体引起。在牛坏死性支气管肺炎中应怀疑牛支原体感染，特别是在肺部坏死是围绕气道的脓性肉芽肿性炎症一部分的情况下。伴有脓性肉芽肿性炎症的干酪样坏死模式是牛支原体感染的特征，而凝固性坏死模式与溶血曼氏杆菌和睡眠嗜血杆菌感染相似且必须加以区分。
